This invention relates to electric lamps and has particular reference to an improved lamp unit of compact size that employs a convoluted fluorescent lamp as the light source and is adapted for use in residential and commercial lighting fixtures which are designed for incandescent-type lamps.
Fluorescent lamp units that are specially constructed for use in conventional lighting fixtures having screw-type sockets are well known in the art. A lamp unit of this type having a cylindrical envelope that contains concentric annular partitions (or which is made from tubing that is bent upon itself to provide a U-shaped bulb or one which is twisted into spiral shape) is disclosed in U.S. Pat. No. 3,551,736 to Doehner. The fluorescent lamp component has prong contacts which permit it to be plugged into a ballast unit which, in turn, is designed to be coupled to a screw-type base member that contains the starter and condenser components of the lamp-energizing circuit.
A lamp assembly having plug-in adapter means which accommodates a conventional straight tubular fluorescent lamp and couples the lamp to a threaded base component that contains a ballast transformer and thus permits the lamp assembly to be screwed into an incandescent lamp socket is disclosed in U.S. Pat. No. 3,815,080 to Summa.
In pending United Kingdom Application No. GB 2,003,314A (published Mar. 9, 1979) of Moerkens et al. there is disclosed a lamp unit comprising a U-shaped fluorescent lamp that is enclosed by a tubular glass envelope and mounted together therewith on a housing which contains the ballast and starter components of the lamp-operating circuit and is terminated by a screw-type base that will fit into a socket designed for incandescent lamps. Fluorescent luminaires that consist of a triple-U-bent fluorescent lamp that is mounted on a module that contains circuit components (such as a ballast) and is terminated by blade-like contacts or a screw-in base member are disclosed in Japanese Design Patent No. 437,859 to Takeda et al. (registered Sept. 20, 1976 and Dec. 20, 1977 on Design Applications Showa 49-28293 and Showa 49-28295).
The aforementioned pending application Ser. No. 011,832 of Skwirut et al. discloses a compact lamp unit which contains a triple-U-bent fluorescent lamp component that is supported within a vented protective cover by a module which is also vented and contains a lamp-supporting member and various lamp-circuit components and is terminated by a screw-in type base. The FIG. 8 embodiment of this application discloses a plug-in type fluorescent lamp and module combination.
The aforementioned pending Young application Ser. No. 097,279 discloses a similar lamp unit that contains a larger multi-U-bent fluorescent lamp which has a higher light output and is mounted within a vented protective cover by a base module that is also provided with vent openings and is constructed to support the lamp component and accommodate various circuit components.
The aforementioned pending Morton application Ser. No. 097,278 discloses a vented single-ended fluorescent lamp unit which contains a multi-U-bent lamp component that is mounted on a base component of such construction that it not only supports the lamp component but encloses and physically separates the ballast and capacitor components of the operating circuit.
While the prior art lamp assemblies were satisfactory from the standpoint of providing a compact fluorescent lamp unit that can be used in incandescent-type lamp sockets and fixtures, the construction of the base module in some units was such that only the lamp component could be removed from the unit and replaced. In addition, the lamp-supporting portion of the module was so designed that it restricted the free flow of air through the unit to some degree, even in those cases where the support member was apertured.
The present invention corrects both of these deficiencies by providing a compact lamp unit which contains a convoluted fluorescent lamp that is supported within a vented protective housing by a vented module which includes a base member and has a plate-like mounting member that not only supports the lamp component and various circuit components in such a manner that they can all be readily replaced, but is so constructed that it enhances rather than restricts the flow of cool air through the vented module and protective housing members of the unit. In accordance with a preferred embodiment, these very desirable functional and marketing advantages are achieved by securing a separately-formed plate-like mounting member in transverse position within the module and providing it with various connector and/or socket components and features that it mechanically and electrically couples the fluorescent lamp and expendable circuit components to the module in plug-in like fashion. In addition, the plate-like mounting member is of such size and so oriented that its periphery is spaced inwardly from the surrounding portion of the module and thus provides a peripherally-extending passageway which insures that air will flow freely through the lamp unit via the vent openings in the module and cover components.